ObjectiveRecently, an increasing number of Korean male conscripts have been retiring because of military maladjustment despite the presence of qualifying medical and psychological screening tests in the Korean army. These problems suggest the presence of a common personality problem. To further examine this possibility, the present study used Cloninger's psychobiological model to investigate the temperament and character of soldiers suffering from military maladjustment.MethodsSeventy-nine maladjusted male conscripts and eighty-seven controls enrolled at the 1596th unit from April 2011 to June 2012 participated in the present study. To measure participant personality, we used the Korean version of the Temperament and Character Inventory, Revised-Short. We used logistic regression analysis to examine the association between TCI-RS scores and risk of military maladjustment.ResultsThe maladjustment group had a lower rank, socioeconomic status, education level, and a shorter duration of military service than the control group. The harm avoidance and self-transcendence scores were significantly higher in the maladjustment group, with lower scores for reward dependence, persistence, self-directedness, and cooperativeness scores. However, of these measures, only low cooperativeness was associated with an increased risk of military maladjustment.ConclusionThese results suggest that a low level of cooperativeness can predict military inadequacy. Maladjusted male conscripts may have different personality characteristics from normals. To validate our results, further follow-up or cohort studies with a larger sample will be required.